F T/R Competition Sorting cases by weight

[HighRez]

I suppose I should post this on the Handloading Forum, but perhaps the moderators will allow it here for loaders and shooters who will consider my question based on load development for F-Class.

I have been both shooting and handloading for about a year, with all my handloading being for my .260 Remington. Now that I'm working toward F-T/R, it's time to start loading for my .308. I have about 500 once fired Federal GMM cases (fired in my rifle) that I'd like to load for practice shooting.

Knowing that the Federal brass has a reputation for inconsistent internal volume, which should in theory yield inconsistent pressure and velocity, I did a little testing. 20 randomly selected Federal cases, still having fired primers, ranged in weight from 180.2 gr. up to 183.2 gr, a 3 grain spread. Nine out of the 20 weighed between 182.2 and 182.8 grs.

Out of curiosity, I also weighed 20 random Lapua .260 Rem cases. I was amazed. There was only a .8 gr spread, with 19 of the 20 being with .5 gr. of each other.

So you know where I'm going. In developing an accurate .308 practice load how particular should I be on sorting the Federal brass? Should I weigh them all and identify a .5 grain range like the Lapua, then use only the brass that falls within that range? I'm certain you guys are particular about your match loads but how about your practice loads? Personally I've always believed in practice like you compete ... which could mean just buying Lapua brass, but I sure would like to use these Federals for something. Thanks for the input.

 

[scaxeman]

Re: Sorting cases by weight

Federal brass tends to be on the soft side, so most reloaders tend to shy away from it. It works brilliantly well for it's intended purpose (make *very* accurate factory ammo), but for repeated reloading, there are better choices.

Lapua is definitely one of these choices, one of their strong suits is the small case weight spreads. Winchester brass is another choice, for high-pressure F-T/R loads, I've found both Lapua and Winchester brass to 'wear' about the same (6-8 reloads), but you'll have to do more sorting and probably work with the Winchester brass. Conversely, the Winchester brass is around 2/3 the price of Lapua.

For true weight sorting, pull the primers, and clean them... it'll give you a better comparison. When I weight sort, I stratify, this allows me to use virtually all of my brass (from whatever manufacturer) vs. chopping the "bell" out of a bell curve of weights and discarding the fringes. It gives me (over a 15 or 20 round competition string) basically the same tight weight spread.

Hope this helps,

Darrell

 

[nimoz]

Re: Sorting cases by weight

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HighRez</div><div class="ubbcode-body">I suppose I should post this on the Handloading Forum, but perhaps the moderators will allow it here for loaders and shooters who will consider my question based on load development for F-Class.

I have been both shooting and handloading for about a year, with all my handloading being for my .260 Remington. Now that I'm working toward F-T/R, it's time to start loading for my .308. I have about 500 once fired Federal GMM cases (fired in my rifle) that I'd like to load for practice shooting.

Knowing that the Federal brass has a reputation for inconsistent internal volume, which should in theory yield inconsistent pressure and velocity, I did a little testing. 20 randomly selected Federal cases, still having fired primers, ranged in weight from 180.2 gr. up to 183.2 gr, a 3 grain spread. Nine out of the 20 weighed between 182.2 and 182.8 grs.

Out of curiosity, I also weighed 20 random Lapua .260 Rem cases. I was amazed. There was only a .8 gr spread, with 19 of the 20 being with .5 gr. of each other.

So you know where I'm going. In developing an accurate .308 practice load how particular should I be on sorting the Federal brass? Should I weigh them all and identify a .5 grain range like the Lapua, then use only the brass that falls within that range? I'm certain you guys are particular about your match loads but how about your practice loads? Personally I've always believed in practice like you compete ... which could mean just buying Lapua brass, but I sure would like to use these Federals for something. Thanks for the input. </div></div>

I, with my limited experience, have found case <span style="font-weight: bold">weight </span>to be non relevant. Case and neck <span style="font-weight: bold">length</span> is much more important, and I would believe this relates to neck tension.
Random lengths vs sorted gave a huge difference in group sizes for me.
I use Lapua .308 brass, which my confirm your findings.
I'm an addict and still learning

 

[Greg Langelius *]

Re: Sorting cases by weight

Everybody has their own pet theories about cases and consistency, and how any or all of it adds up in the balance regarding accuracy.

Does it matter? I'm pretty certain it does, but I'm also equally certain that completely resolving this and all other handloader-controllable issues is still not going to get you that proverbial 0.000" group.

Chasing perfection is a predestined cause. It never happens, and if it does, it'll never happen twice.

Happily, perfection isn't what's actually needed. Good is good, better is better, and somewhare along that line of reasoning it will become necessary to decide whether one prefers to spend one'e time at the loading bench, or actually shooting. Sometime, somehow, a compromise will need to be reached.

I chose to apply my bias toward shooting.

Greg

 

[XTR]

Re: Sorting cases by weight

I shoot WW brass. If you try to weight sort it you get weights all over the board; however, much of that is because they have different extractor groove cuts not internal volume differences. I find a number of cases out of a batch of 500 that won't fit in my shell holder because the extractor groove is not deep enough, that adds a lot of weight.

WW is obviously not as high quality as Lapua; on the other hand as noted it costs 1/3 to 1/2 less and I can't see a significant difference in accuracy of my loads between the two. If you were shooting bench rest and looking for and measuring .050 MOA variations maybe it's worth it, but in our world where I need to hold .5MOA vertical for the X ring WW works great for me.

 

[leadbullet]

Re: Sorting cases by weight

I have been weighing the bullets and that is a real pain, i have been thinking of weight sorting the brass but so far I will pass on it since achieving a hair better than half MOA and that plenty good for me.
hope this helps.

 

[HighRez]

Re: Sorting cases by weight

Thanks guys ... I appreciate the input. Out of curiosity while I was weighing the Federal brass, I tested the difference in internal volume by filling the heaviest and lightest cases with water, then weighing the water. It's the only way I could figure to compare the two. The difference in water weight was .4 gr. and I don't know what that means in terms of a difference in volume that would equate to erratic pressure and velocity. In the real world it may not mean much, but for me just learning this stuff, it's an interesting mental exercise. And agreeing with Greg, I'd rather be shooting.

Exercise complete. Based on your input (and the fact that I now have 101 posts) I think I'll post the 500 Federal cases for sale, put the proceeds toward some Lapua brass and move on to whatever is next. Thanks again.

Bob

 

[Greg Langelius *]

Re: Sorting cases by weight

That could work. But consider this.

I did blind tests of weighed and unweighed cases (and bullets) and found that except for the most (BR) demanding of applications, the performance variances were masked by the overall 'white noise' of innacuracy factors that are simply beyond the handloader/shooter's control. BR shooters are breed unto themselves. BTDT, I like what we do here better.

For practical purposes, the major manufacturers' quality control standards, for bullets definitely, for brass usually, are tight enough to trust without further verification. You could just as effectively transfer that time outlay into shooting.

I say this often; do the basic reloading steps with due diligence. While there will be some sacrifice in accuracy as opposed to doing all the more arcane additional steps, that diligence will make the sacrifice acceptably small.

Use reasonable care when handloading, spend the saved time shooting.

When I used to measure case capacity, I used a case with a primer in it, and filled the case to overflowing with the powder I'd be using via a drop tube. That way, any capacity variances had an immediate and relevent meaning. .4gr of water means nothing to me. .2gr of powder has a real meaning for me.

Greg